Introduction:

Labview is the programming language developed by National Instruments (NI).
It is widely used in test and measurement industry for various applications
such as automation, conformance testing, pre-certification testing and more.
It is adopted by industry in various discipline including wireless, telecom,
mechanical and electrical domains. National Instrument provides training on
Labview at various levels. Various labview certification courses will be available
from National Instruments. This labview tutorial covers very basic knowledge on labview
programming for beginners. Programs developed under labview environment are named as VI.
VI stands for Virtual Instrumentation.

Creating VI:

After installing labview and clicking and opening blank VI following two windows open up.

1. Front panel - It provides user interface functionalities of the design under development using labview.
Basically it provides place where one can keep controls and indicators mainly
used to provide inputs and take outputs from the VI.
This also helps interface Vis together in the bigger system by
connecting outputs of one VI with the inputs of the other VI.

2. Block Diagram -This window contains source code in the form
of graphical icons and wires/signals.

In addition there is icon and connector pane which helps use VI as sub VI in a larger bigger system. For Example as mentioned below scrambler is used as sub VI in a transmitter of a wimax physical layer. This is similar to subroutine or function as used in text based programming languages (Pascal, c).

Icon of each VI is visible on the top right corner of both the block diagram and front panel windows. One can edit the icon only in front panel window. Each icon contains text, image and both for function representative purpose.

Use Edit Icon to add text and graphics and colors.

Use Show connector feature to add and remove terminal to the icon (i.e. VI).
These terminals acts as an input and output terminals and will hence help pass
arguments to the VI and take out the arguments from a VI.

Data types supported in Labview

Labview provides colors, styles, and thicknesses
depending on data types used as shown in the figures below,
so that they can be easily identified by the Labview programmer
and help connect appropriate wires between the two VIs.

Figure 1 of data type supported in labview

Programming Syntax

Similar to other programming language labview
also provides functions for For Loop, While Loop,
case structure, Shift register, Array, File I/O, Case Structure,
graphs and more. It provides various string related functions.
Various functionalities specific to particular domain such as
signal processing are also available and provided in labview
programming language. One can drag and drop the icon in the block
diagram panel and use right click of mouse and help to go in detail
of each of the functions. This helps in speed up of programming development.

Example Implementation using Labview

In this section we will see example implementation of scrambler
module as mentioned below in the circuit; it takes input seed and
data as input and provides scrambled data as output.

Implementation of the above scrambler circuit module as per labview programming constructs is depicted below.